Generally, various electronic devices are being developed through the development of electronic communication technology, and these electronic devices are increasingly emphasizing splendors of a design along with convenience of the user's operation. What is emphasized in this trend is the diversification of input devices represented by keyboards or keypads.
Input devices are used in various types of display systems that provide information to users, such as portable terminals, notebooks, smart phones, smart pads, smart TVs, and the like. Recently, a method of inputting a command signal by using a touch has been used in addition to a method of inputting using an operation key, a dial, or the like in conjunction with the development of electronic devices.
The touch input device, which is one of the input devices constituting an interface between the information communication devices using various displays and the user, enables an interface between an information communication device and a user by allowing the user to directly touch or approach the touch pad or the touch screen by using a finger or an input tool such as a touch pen.
The touch input device is utilized by various devices such as an automated teller machine (ATM), a personal digital assistant (PDA), and a mobile phone because the touch input device may be easily used by anyone of all ages, just by touching a finger or an input tool such as a touch pen. It is also widely used in many fields such as banks, government offices, sightseeing and traffic information.
Recently, efforts have been made to apply touch input devices to health or medical products and vehicles. In particular, the use of the touch panel is increasing because it may be used together with the touch screen or may be used independently in the display system. Recently, a function of inputting a gesture in addition to a function of moving a point by using a touch has been developed. In the case of a touch input device capable of inputting a gesture, efforts to improve the recognition rate of a gesture continue.
As a method of implementing a touch input device capable of touch operation, a resistance method, an electrostatic capacitance method, a surface ultrasonic method, and a transmitter method are used. Among them, as a touch input device using the electrostatic capacitance method, there is a type in which electrode patterns are formed in a direction crossing each other and a change in electrostatic capacitance between electrodes is detected when an input means such as a finger touches the touch input device to detect an input position. Alternatively, there is a type in which the equal potential with the inphase is applied to both ends of a transparent conductive film and a weak current flowing when the input means such as a finger touches or is close to the touch input device to form a capacitor is detected to detect an input position.
In general, the touch input device is composed of a two-panel laminated structure in which a first panel and a second panel are bonded by using an adhesive, wherein the first panel includes first sensing patterns arranged in a first direction (e.g., x-axis direction) on the first substrate and a plurality of first metal patterns electrically connecting sensor circuits for calculating the position of the first sensing patterns, and the second panel includes second sensing patterns arranged in a second direction (e.g., y-axis direction) on the second substrate and a plurality of second metal patterns electrically connecting sensor circuits for calculating the positions of the second sensing patterns.
In addition, Korean Laid-Open Patent Application No. 10-2008-0110477 discloses a one-piece type two-layer electrostatic capacitive touch panel.
However, the conventional electrostatic capacitive touch pad is only formed on a gentle curved surface, and there is no technology for forming a touch pad on a complex curved surface.